Transcript for Trump asked former chief of staff about special counsel team: Sources

New developmentsv in the Russia investigation. There are reports now that president trump has asked witnesses about their questioning by Robert Mueller and his team, asking, were they fair? Here's ABC's chief justice correspondent, Pierre Thomas tonight. Reporter: Tonight, Donald Trump's former campaign manager, Corey Lewandowski, grilled by congressional investigators. Were you able to answer all the questions? I answered every relevant question you could imane. I just spent 12 hours of my life I'll never get back. There was no collusion no cooperation, no coordination. Fact. Reporter: His testimony comes amid new questions about whether the president has been asking witnesses interviewed by Robert Mueller, what was asked. Tonight, there is new scrutiny on a conversation between the president and his former chief of staff reince Priebus, after Priebus was interviewed by Mueller's team. Sources say president trump asked Priebus if the special counsel's team had been, quote, nice, and if Priebus had been treated fairly. Now, sources close to the president describe the conversation as, quote, innocent. And tonight, new focus on whether the president-elect and his team were trying to set up a back channel with Putin before the inauguration. At issue is a meeting. At the meeting, this man. Erik prince. The former blackwater CEO -- he is also the brother of education secretary Betsy Devos. Erik prince was in the Seychelles two weeks before the inauguration. Also there, a Russian banker. Prince has said their meeting was unplanned, a chance encounter in the Seychelles while he was on a business trip. "Met him down in the bar after dinner," prince said of his encounter with the Russian banker. "We talked for 30 minutes over a beer, and that was it." And he says, the president-elect didn't know. Was anyone on the trump team aware that you were at this meeting? No one was aware from the trump team that I was even there. Reporter: But "The Washington post" is reporting there is another version of the story. That there was someone else there who now says it was not by chance. And that it was specially set up to discuss relations between the U.S. And Russia. That person is George Nader, a Lebanese American who says he helped set up the meeting. And who is now reportedly cooperating with Robert Mueller. We want to hear from George Nader in our Russian investigation. If the accounts about Mr. Nader are true, then Erik prince lied to congress. That's a problem. All right. Let's get to Pierre Thomas with us live tonight. Let's get back to what you reported there. Corey Lewandowski, and we're going to see noneberg after seeing the counsel might have something on the president? Reporter: That's right, David. We expect nunberg back in the news after all the back and forth over whether he would testify. He told us today he is going to appear before Mueller's grand jury tomorrow. David, we'll see. Pierre, thank you.

This transcript has been automatically generated and may not be 100% accurate.

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